╥EPRINTED FROM THE ┴PRIL, 1986 ISSUE OF ╨APER ═ODEM, A ╬EWSLETTER FROM ╬ORTHERN ╔LLINOIS.
BY ╠YLE ╟IESE
╘HE SUBJECT OF THIS MONTH'S COLUMN IS SOMETHING THAT ╔ DID SEVERAL MONTHS AGO. ╔ TOOK MY ═╙─ ╙─-1 AND CONVERTED IT INTO A DUAL DRIVE. ╔T WAS NOT VERY HARD TO DO AND CAN BE DONE WITH ONLY A FEW PARTS. ╘HE MOST EXPENSIVE PART OF THE DEAL IS THE DISK DRIVE ITSELLF. ╔ HAVE FOUND ONLY TWO SUPPLIERS OF THEM. ┬OTH OF THEM ADVERTISE IN THE ├OMPUTER ╙HOPPER. ╘HE FIRST IS ╠─╠ ┼LECTRONICS IN ╩UPITER, ╞LA. ╚E ADVERTISES IN THE CLASSIFIED SECTION UNDER DISK DRIVES.
╘HE OTHER IS ╠OLIR ╠CTRONICS. ╘HEY USUALLY HAVE A BIG AD ELSEWHERE IN THE ├OMPUTER ╙HOPPER. ╘HE UNITS THEY HAD WERE USED AND IN LIMITED SUPPLY.
[┼D NOTE, 12/86: ╬EITHER IS BELIEVED TO HAVE ╘┼├ DRIVE MECHANISMS CURRENTLY.]
╔ AM SURE THAT OTHER SUPPLIERS CAN BE FOUND BUT THE ╘┼├ ╞┬501 DISK DRIVE THAT ═╙─ USED IS A ╙INGLE ╙IDED, ╙INGLE ─ENSITY DRIVE. ┴LMOST ALL OF THE ADS YOU SEE FOR DRIVES ARE FOR DOUBLE SIDED AND/OR DOUBLE DENSITY DRIVES. ╙O THEY ARE NOT READILY AVAILABLE.
╘HE ═╙─ DRIVE WAS ENGINEERED TO BE A DUAL DRIVE (THAT IS 2 UNITS IN ONE CASE WITH ONE DISK DRIVE CONTROLLER). ╫HEN THEY MADE THE SINGLE THEY MERELY TOOK OUT ONE OF THE DRIVES AND IN SOME MODELS TOOK OUT ONE OF THE 2╦ ╥┴═ CHIPS.
╘HE ═╙─ WHEN POWERING UP TRIES TO INITIALIZE BOTH DRIVES AND IF THE SECOND IS MISSING THEN GOES INTO THE SINGLE DRIVE MODE. ╧NE OF THE DIFFERENCES YOU CAN SEE IS THE WAY THE DRIVE ACTIVITY LIGHT WORKS.
╔N THE DUAL UNIT THERE ARE 3 LEDS. ╔N THE SINGLE THERE IS ONLY ONE. ╘HAT SINGLE (THE TOP ONE ON THE DUAL) LED GOES FROM GREEN TO RED WHENEVER A FILE IS OPEN OR WHEN LOADING OR SAVING DATA. ╧N THE DUAL THE POWER LED IS GREEN AND STAYS THAT WAY. ╘HE OTHER LEDS ARE FOR EACH OF THE DRIVES AND ARE OFF UNTIL YOU ACCESS ONE OF THE DRIVES. ╘HEN THEY BEHAVE LIKE THE RED PORTION OF THE POWER LED IN SINGLE MODEL.
╘HE FIRST THING YOU NEED TO DO IS OPEN UP YOUR SINGLE DRIVE AND LOOK AT THE MEMORY CHIPS IN IT. ╞ROM THE FRONT ON THE TOP ROW ARE THE MEMORY CHIPS. ═╙─ HAS PLACES FOR FOUR 2╦ ╥┴═ CHIPS ON THE DRIVE CONTROLLER BOARD.
╘HE FIRST TWO MEMEORY CHIPS ARE INSTALLED IN ALL DRIVES. ╘HE THIRD IS NEEDED FOR THE DUAL ONLY AND THE FOURTH ONE IS NOT FOUND IN DUALS. ╔N SOME OF THE VERY EARLY SINGLES ═╙─ POPULATED ALL FOUR MEMORY CHIP LOCATIONS. ╔F YOU HAVE ONE OF THESE SINGLES (╔ DID) YOU DON'T NEED TO ADD A MEMORY CHIP. ┬UT IF YOU NEED ONE, THEY ARE A ╙YNERTEK ╙┘2128, SAME AS A ╬ATIONAL ╙EMICONDUCTOR ╚═6116╨-4.
╘OWARD THE BACK YOU WILL SEE TWO CABLES GOING FROM THE CONTROLLER BOARD TO THE DISK DRIVE. ┘OU HAVE TO PARALLEL BOTH INTO THE NEW DRIVE AND WITH THE THIRD ╥┴═ CHIP IN PLACE YOU ARE ACTUALLY DONE AND HAVE A DUAL UNIT.
╘HE RIBBON CABLE SENDS AND RECEIVES THE SIGNALS FROM THE CONTROLLER TO THE DRIVE. ╘ELLING THE DRIVE TO MOVE THE HEAD IF NEEDED AND TAKING AND SENDING THE SIGNALS FROM THE HEADS CONTAINING THE ACTUAL DATA. ╘HE DRIVE ALSO TELLS THE CONROLLER OVER THE CABLE IF THERE IS A DISK IN THE UNIT AND IF THE DISK HAS THE WRITE PROTECT TAB ON OR OFF. ╘HE CONTROLLER MUST ALSO TELL WHICH DRIVE IT WANTS TO TALK TO IN THE DUAL UNIT.
╘HE OTHER CABLE CARRIES THE POWER NEEDED TO RUN THE DRIVE. 5 VOLTS ─├ TO POWER THE ELECTRIONICS ON THE DRIVE AND 12 VOLTS ─├ TO TURN THE MOTORS ON THE DRIVE.
╔ PURCHASED MY DRIVE FROM ╠─╠ IN ╩UPITER, ╞LA. ╚E WAS ABLE TO SELL ME A SHORT PIECE OF RIBBON CABLE AND THE NECESSARY CONNECTORS. ╞OR THE POWER CABLE HE HAS A SMALL ┘-POWER KIT THAT WILL TAKE THE ONE POWER CONNECTOR AND TURN IT INTO TWO FOR YOU.
╘HE CONNECTORS THAT ╠─╠ SOLD ME TO TIE THE TWO CABLES TOGETHER WERE CALLED AN ╠─┼ MALE RIBBON CONNECTOR AND A ╠─╙ FEMALE RIBBON CONNECTOR. ╘HEY CONTAIN TWO ROWS OF PINS TO INTERCONNECT. ╧N THE OTHER END OF YOUR NEW PIECE OF RIBBON CABLE, YOU PUT A CARD EDGE CONNECTOR TO ATTACH TO THE DISK DRIVE.
╘HE HARDEST PART OF THE WHOLE CONVERSION IS PUTTING THE CONNNECTORS ON THE RIBBON CABLE. ╔ FOUND THAT THE VISE MOUNTED ON MY WORK BENCH WORKED FINE. ╚OWEVER, ╔ WOULD CAUTION THAT YOU DO NOT APPLY TOO MUCH TENSION WITH A VISE AS YOU COULD CRUSH THE CONNECTORS.
╔T IS EASY TO GET THE CONNECTORS ON THE NEW PIECE OF RIBBON CABLE. ╨UTTING THE ONE ON THE EXSITING CABLE IS NOT AS EASY THOUGH AS IT IS HARD TO DO WHILE THE CABLE IS CONNECTED TO THE CONTROLLER CARD. ═╙─ USED WHAT IS CALLED A SOLDER TRANSITION CONNECTOR. ╘HE CABLE IS NOT REMOVABLE FROM THE CONTROLLER CARD.
╔N ORDER TO GET THE CONNECTOR ON THAT PIECE OF CABLE, IT TAKES ABOUT FOUR HANDS AND A LITTLE PATIENCE. ╙OMEONE NEEDS TO HOLD THE CONTROLLER CABLE CLOSE TO THE VISE WHILE HOLDING ON TO THE CONNECTOR WHILE KEEPING THE RIBBON CABLE STRIAGHT INSIDE THE CONNECTOR ╫╚╔╠┼ TIGHTENING THE VISE DOWN!
╫╚┼╫! ╠IKE ╔ SAID IT TAKES MORE THAN ONE PAIR OF HANDS IN THIS PHASE OF THE PROJECT.
╬OW YOU CAN HOOK UP THE NEW DRIVE AND SEE IF IT WORKS. ┬UT BEFORE YOU POWER UP THE NEW DRIVE, YOU HAVE TO CHANGE THE DRIVE NUMBER ON THE UNIT. ╬EAR THE REAR OF THE DRIVE, YOU WILL FIND AN OPTION PLUG. ╘HE ORIGINAL DRIVE WILL BE SET FOR DRIVE 0. ═OVE THE OPTION PLUG ON THE SECOND DRIVE TO 1.
╧N THE ORIGINAL DRIVE YOU MUST REMOVE THE TERMINATOR RESISTOR PACK. ╘HEY ARE HOLD UP RESISTORS AND TERMINATE THE DATALINES. ┘OU ONLY WANT ONE SET IN THE SYSTEM AND IT SHOULD BE ON THE LAST DRIVE, IN THIS CASE THE NEW DRIVE. ╘HE RESISTOR PACK IS AT THE REAR OF THE DRIVE AND IS IN AN ╔├ SOCKET, DESIGNATED ╥┴11. ┴LL OF THE ╔├S ON THE DRIVE ARE SOLDERED IN SO IT WILL BE EASY TO SEE IT. ├AREFULLY REMOVE THE RESISTOR PACK ON DRIVE 0 (YOUR ORIGINAL ONE). [┼D NOTE: ╘HIS IS IMPORTANT.]
╧N THE SURFACE THAT COMPLETES THE PROJECT. ┴FTER YOU PLUG IN THE TWO CABLES, IT SHOULD WORK. ┬UT IT SHOUD BE POINTED OUT THAT SOME MINOR MODIFICATIONTS TO THE NEW DRIVE ARE NEEDED IN ORDER TO READ THE ╟├╥ FORMAT THAT ├┬═ USES, RELIABLY. ╘HE DRIVES WERE MADE WITH ═╞═ (WHICH IS A DIFFERENT MANNER OF RECORDING THE INFORMATION ON THE DISKETTE) AND ALSO YOU NEED TO ADD TWO LEDS.
╔T IS EASY TO SEE THE ╟├╥ MODIFICATION WHEN YOU LOOK AT THE PRINTED CIRCUIT BOARDS ON THE TWO DRIVES. ╘HE DRIVE COMES WIHT 1/8 WATT RESISTORS INSTALLED FROM THE FACTORY. ╘HE MODIFICATION INVOLVES CHANGING/ADDING 3 RESISTORS. ═╙─ USED 1/4 WATT RESISTORS FOR THE MODIFICATION. ╘HE DIFFERENCE IN SIZE OF THE RESISTORS MAKES THEM EVERY EASY TO SPOT ON THE PRINTED CIRCUIT BOARD.
╥ESISTOR ╥9 IS REPLACED WITH A 560 OHM RESISTOR. ╥ESISTOR ╥15 IS PARALLELED WITH A 56╦ OHM RESISTOR. ┴ND ╥22 IS CHANGED TO AN 10╦ OHM RESISTOR. ┬E SURE TO USE 1/4 WATT OR LESS RESISTORS. ╬OT THAT PERFORMANCE WILL CHANGE BUT YOU WILL HAVE TROUBLE WITH BIGGER RESISTORS. ┴GAIN YOU MIGHT TRY TO RUN YOUR NEW DRIVE WITHOUT CHANGING THE RESISTORS AND SEE IF IT WILL WORK WELL, BEFORE GOING TO THE TROUBLE FO CHANGING RESISTORS. ┴S WAS STATED IT IS JUST TO MAKE THE DRIVE READ THE ╟├╥ FORMAT BETTER.
[┼D NOTE: ╘HE MODIFICATION DESCRIBED, KNOWN AS '┬' MODIFICATION, IS ONE OF THREE USED BY ═╙─. ╘HE MOST RECENT DESCRIBED IN THE ═╙─ ╙ERVICE ═ANUAL, MODIFICATION '├', CONSISTS OF ADDING A 56╦ OHM 1/4 WATT RESISTOR IN PARALLEL WITH ╥15, REMOVING ╥10 (10╦ OHM), AND SHORTING ╠3 WITH A PIECE OF BUSS WIRE, LEAVING ╥9 (220 OHM) UNCHANGED.]
┴FTER YOU DO THAT, YOU WILL WANT TO ADD THE TWO LEDS NEEDED TO SHOW DRIVE ACTIVITY AND ERRORS FOR EACH DRIVE UNIT. ╩UST UNDER THE GREEN LED WILL BE A PLACE FOR TWO MORE LEDS. ═OST ANY LED WILL WORK AS LONG AS YOU DON'T REVERSE THE LEADS. ╘HE VOLTAGE WILL NOT DAMAGE THE UNIT IF YOU DO REVERSE IT, IT JUST WON'T LIGHT UP.
┴LL THAT REMAINS IS TO HOUSE YOUR NEW DUAL DRIVE IN A NEW CASE AND YOU WILL BE ALL SET. ╔ WENT TO ═╙─ DIRECTLY AND PURCHASED THEIR DRIVE CABINET. ╘HEY INSISTED ON SENDING IT OUT ╒╨╙ ├╧─. ╘HE TOTAL COST OF PARTS WAS ABOUT $140.00, BUT ╔ THINK THE PRICES HAVE DROPPED A LITTLE SINCE ╔ BOUGHT MINE.
╫AS IT WORTH IT? ┘┼╙! ╔T IS WONDERFUL TO BE ABLE TO COPY A DISKETTE (THAT DOES NOT HAVE ANY READ ERRORS) IN UNDER 2 MINUTES. ┴ND THAT INCLUDES FORMATTING THE DESTINATION DISKETTE! ┬EING ABLE TO COPY FILES FROM ONE DISKETTE TO ANOTHER WITHOUT LOADING IT INTO THE COMPUTER FIRST (╓┼╥┘ TIME CONSUMEING!) IS GREAT! ╔T DOES TAKE LONGER TO TRANSFER A MEDIUM SIZED FILE THAN TO COPY A WHOLE DISKETTE. ┬UT IS IS VERY HANDY WHEN SORTING FILES AND CERTAINLY IS FASTER THAN LOADING THE FILE INTO THE 64 AND SENDING IT OUT AGOAIN.
╔F ANYONE HAS ANY QUESTIONS OF COURSE YOU CAN GIVE ME A CALL DURING WORK HOURS AT 815-338-9960 OR AT NIGHT AT 815-338-1072.
